Nichols was born in Milford, Utah.
As an animator for Disney, his first credit was on the film Pinocchio, where he was the lead animator for the villainous Coachman. Later he directed many projects, including Morris the Midget Moose, Toot, Whistle, Plunk and Boom, and numerous cartoons involving the character Pluto and the final season of The New Adventures of Winnie the Pooh on ABC.
At Hanna-Barbera, he directed episodes of The Jetsons, Jonny Quest and The Flintstones. With Iwao Takamoto, he co-directed the feature-length animated film Charlotte's Web (1973). Later, he created Hong Kong Phooey and Goober and the Ghost Chasers, and directed many other Hanna-Barbera cartoon series from the 1970s, including The Scooby-Doo Show.
He is also credited as Nick Nichols on Scooby's All-Stars on ABC (the second-season title of Scooby's All-Star Laff-A-Lympics).